Antenna arrangement for short-wave apparatus



June 28, 1927. A. EsAU ANTENNA ARRANGBIENT FOR SHORT WAVE APPARATUS Filed Oct. 8, 1926 Patented June. 28, 1927.

UNITED STATES ABRAHAM, ESAU, or JENA, GERMANY.

ANTENNA ARRANGEMENT For. SHORLWAVE Humans.

Application filed October 8, 1926, Serial No. 140,378, and in Germany 0ctober 7, 1925.

This invention relates to antenna arrangements particularly for short-wave apparatus. r

In known short-wave apparatus the antenna is connected to the oscillation circuit either inductively or through capacity. In accordance with my invention the antenna is connected by a metallic .conductor. Experiments with antennae of this kind have shown that the best radiation of short-waves is obtained when the connection of the wave carrying member or coil of the oscillation circuit to the earth through a conductor or condenser is omitted and the antenna is connected to a node of voltage in a wave carrying member of the apparatus.

A further feature of the invention consists in the connecting of a plurality of antennae to a number of nodes of voltage whereby a reflecting member associated with the anis equal to a quarter of a wave length or to an uneven multiple of same. If the antenna length differs from these values the oscillations cease. I employ this fact as a means for controlling the radiated energy of shortwave senders by changing the length of the antenna at will. This is preferably effected by adding or subtracting a section of the antenna by means of a key, switch or the like. An advantage gained hereby is that there is no consumption of energy in the intervals between the closures of the signalling key.

The invention is illustrated in the drawing in which Fig. 1 shows an arrangement in which one antenna is employed while Fig. 2 shows an arrangement in which a plurality of antennae are used. I In both figures, which show oscillation producers, 11 denotes the source of anode current, D and D are high frequency choking coils, R is a non-inductive resistance, W a heating current resistance, and E the heat ing or filament battery. C is a condenser and L a wave carrying member or coil of the oscillation circuit. In the wave carrying coil L of Fig. 1 there is a node of voltage (2 to which the antenna A is connected. In the wave carrying coil L of Fig. 2 there are two nodes of potential (1 and a, to which the antennae A and A are connected. To

enable the length or lengths of the antenna or antennae to be changed they may be made of sect-ions. In the drawing sections A are shown that can be connected to and disconnected from the antenna proper by means of keys or switches T.

t-enna the results hereinbefore mentioned are obtained.

I claim:

1. Antenna arrangement for shortwave radiation, comprising a closed oscillation circuit including a Wave-carrying coil isolated from the earth, and a wave radiator in direct conducting connection with a node of voltage of the Wave carrying coil in said closed circuit.

2. Antenna arrangement for short-wave radiation, comprising a wave-carrying coil insulated from the earth, and wave radiators in direct conducting connection with nodes of voltage of the wave-carrying coil, whereby aoreflecting member associated with an antenna member is obtained.

3. Antenna arrangement for shortwave radiation, comprising a closed oscillation circuit including a wave-carrying coil isolated from the earth, and wave-radiators in direct conducting connection with nodes of voltage of the wavecarrying coil in said closed circuit, whereby a reflecting member associated with an antenna member is obtained.

4. Antenna arrangement for short-Wave radiation, comprising a closed oscillation circuit including a wave-carrying coil isolated from the earth, a section of antenna in direct conducting connection with a node of voltage of the wave-carrying coil in said closed circuit, another section of antenna, and a device for connecting and disconnecting said sections, whereby the radiation is controlled.

In testimony whereof I have afiixed my signature.

ABRAHAM ESAU.

By thus adding to 60 .or subtracting from the length of the an- 

